Well considering all harvesting perks/tools are broken there isnt much to spec besides what you said and the forge.
Also the day 1 cardio is debatable, you dont need to go to the trader at day 1. Completing trader quest it's 1k exp and well quests are a roll of dice, you can easily run 2km to the trader, to get a 2km away as closest quest. Another aspect is clearing basic quests and running 2km to the trader can be really bad, you get there without anything to sell, dont have money to buy anything, may not have a close quest and at least half day lost for 1k exp.
But I changed my mind and I agree rex and crusher should come first, it will make easier to kill zombies that means it will be faster to level up.